Need a frequent boost? Your battery may not be the issue: Ask a Mechanic

Every week, we take your questions about what is going on under the hood of your vehicle and pose them to a knowledgeable mechanic in the Greater Toronto Area. In today’s column, we learn more about parasitic draw and electric batteries.

Dear Ask a Mechanic,

I own a 2016 Lexus RX350 sport that I park in an underground garage. It failed to start twice last year so I took it into my mechanic and had a new battery installed.

Since then if I don’t drive it for three or four days it requires a boost to start. I have taken it to the Lexus dealership and my mechanic, and both say there is nothing wrong with the vehicle, I just have to drive it more.

This doesn’t make sense to me as I have had vehicles in the past that have sat for weeks and have always started without a problem. – Seeking Assistance

Kirk Paty, owner of R & G Auto Center in Pickering, said there’s an obvious problem. “It should last longer than three or four days,” he said, adding there are many electronics in a vehicle that could cause the battery to have a parasitic draw.

This happens when a vehicle’s battery continues to discharge power when the engine is turned off. Changing the battery is not a probable solution because it’s likely not causing the problem. “It’s difficult to find the problem with those sorts of things,” Paty said. It will require a mechanic meticulously looking through the inner workings of the vehicle to find the culprit. He estimates the process could take them anywhere from five to 10 hours to complete.

Dear Ask a Mechanic,

I’ve been reading a lot about electric batteries, but no one has ever mentioned the life span on these. Is there pollution caused in the production of these batteries? What’s the environmental impact? – Going Green

The lifespan of a battery depends on the type your electric vehicle uses but estimates largely place this between seven to 10 years.

Batteries are also now being made to last longer, and Paty said this is a promising sign of how the technology for electric vehicles is improving.

He also said electric batteries don’t have a huge impact on the environment because when the life span of an old battery comes to an end, it’s either refurbished and given a second life or recycled.

“A lot of a battery is recycled because there’s a lot of metal inside of it,” Paty said.

It should be noted that there is some disagreement, since the mining and production of the elements used in batteries, including rare earth metals, does have an environmental impact. However, there is also the offset that comes from an electric vehicle’s reduction in carbon dioxide emissions compare to traditional internal combustion engines.